U.S. Pat. No. 7,083,364 to Kim entitled “Retaining Wall System With Interlocked Wall-Building Units” describes retaining walls that are used in a wide variety of civil engineering and landscaping applications including, for example, to support slopes and embankments for highways and railways, and to support noise barriers, among other things. More specifically, U.S. Pat. No. 7,083,364 describes a permanent retaining wall structure in which wall building units, such as sand/soil bags, used to make the face of the structure are attached to wall building units in adjacent courses, and preferably to geogrid sheets. Attachment is achieved using an interconnecting member (in the form of a plate) having projections on both sides thereof, which protrude into the wall building units in adjacent courses. The projections also protrude through holes in the geogrid sheets, stabilizing the retaining wall structure and backfill. U.S. Pat. No. 7,083,364 is incorporated herein by reference in its entirety.
A conventional interconnecting member 10 is illustrated in FIGS. 1 and 2, where FIG. 1 is a top isometric view and FIG. 2 is a bottom isometric view. The interconnecting member takes the form of a rectangular plate and includes an upper side 12 and a lower side 14.
Both the upper side 12 and the lower side 14 of the interconnecting member 10 include a plurality of projections 16 in the form of spikes that are used to protrude into sand/soil bags 20, as will be described in connection with FIGS. 3A, 3B, 4A, 4B and 5. The sand/soil bags 20 are made of a geotextile material, which is durable, permits water to flow in and through the bag, and permits seedlings to grow out, while retaining fine soil particles therein. The term sand/soil bag means a bag (or cover) filled with any suitable fill material, including sand, soil, and mixtures thereof, and may also include fill mixed with seeds for grass or other plants.
An exploded front elevation view of a conventional retaining wall system 30 is shown in FIG. 3A, while FIG. 3B is diagrammatic representation of an exploded right end elevation view of the retaining wall system 30. As shown in the figures, the retaining wall system 30 includes a first course 40 of sand/soil bags 20 that extend horizontally and a second course 50 of sand/soil bags (only one bag is shown), which also extend horizontally, but are also vertically adjacent to the first course 40. The first course 40 of sand/soil bags 20 and second course 50 of sand/soil bags are connected to one another by interconnecting members 10.
FIG. 4A is a front elevation view of an assembled retaining wall system 30, while FIG. 4B is a right end elevation view of the retaining wall system 30. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 4A, which shows an interconnecting member 10 engaging two vertically adjacent sand/soil bags 20.
Referring to FIGS. 4A, 4B and 5, interconnecting members 10 are used to construct the retaining wall system 30 by placing them on top of sand/soil bags 20 in a (first) course 40 so that projections on the lower side protrude into the bags. A second course 50 of sand/soil bags is placed on top of the first course and of interconnecting members 10. The projections 16 on the upper side of interconnecting member 10 protrude into the sand/soil bags of the second course 50, and the weight of the sand/soil bags acts on the interconnecting members 10, so that the projections 16 on the lower side 14 protrude into the sand/soil bags 20 in the first course 40. The projections 16 can be configured to fully penetrate the sand/soil bags 20 or to simply indent them. In either case, the projections 16 are considered to “protrude” into the bags.
Interconnecting members 10 are also used to anchor geogrid sheets to the sand/soil bags 20. Geogrid sheets are known and commercially available plastic mesh products commonly used for soil reinforcement and have a plurality of holes therein. Geogrid sheets are affixed to the face of a retaining wall by placing an edge of the sheet over interconnecting members 10 atop a course of sand/soil bags 20, so that the projections 16 on the upper side 12 of the interconnecting member protrude through the holes in the geogrid. When the next course of sand/soil bags 20 is put on top, projections 16 on the upper side of the interconnecting member 10, which already extend through the geogrid, protrude into the underside of the sand/soil bags 20 in the upper course.
Instead of being placed over an interconnecting member 10, a geogrid sheet may be placed directly on top of a course of sand/soil bags 20 with interconnecting members 10 placed over it. In such case, the projections 16 on the lower side 14 of the interconnecting member 10 would protrude down through the holes in the geogrid sheet and into the sand/soil bags 20. In other words, the geogrid may be placed under the interconnecting member 10 instead of over it.
As shown and described in connection with FIGS. 1-5, the projections 16, which are designed to protrude into the sand/soil bags 20 are linearly tapered until they reach a point, wherein the point is furthest away from the face of the upper side 12 (or lower side 14). When forces act on the geogrid, there is some concern that the geogrid will slide off of one or more of the projections 16.
In order to address this concern, U.S. Pat. No. 7,083,364 describes a geogrid holding members that are have a cap, are L-shaped or have a taper that increases as the distance from the face of the upper side 12 (or lower side 14) is increased. The geogrid holding members in the '364 patent are disadvantageous for a number of reasons. For example, using geogrid holding members adds cost since additional material must be used to construct same. As another example, using geogrid holding members may reduce stackability of interconnecting members during shipping.
Accordingly, it would be desirable to develop an interconnecting member which reliably secures geogrid using projections, but without requiring separate geogrid holding members that may reduce stackability.
It would also be desirable to develop an interconnecting member which reduces the likelihood of poor interconnection between vertically adjacent sand/soil bags.
It would also be desirable to permit interconnecting members to be attached to one another in a linear and/or transverse configuration.
It would also be desirable to allow more flexibility in creating retaining wall structures by permitting straps to be attached to interconnecting members.
It would also be desirable to develop more permanent connections between interconnecting members and sand/soil bags.
It would also be desirable to modify the shape of interconnecting members, so as to increase the opportunity for plant growth and reduce the likelihood of obstructing plant growth.